The disclosure of the present disclosure relates to a multi-stage transmission that changes the speed of power transmitted from a motor of a vehicle to an input member to transmit the power to an output member.
Conventionally, a multi-stage transmission of this type has been known which includes two single-pinion type planetary gears, a Ravigneaux type planetary gear mechanism as a compound planetary gear train, four clutches, and two brakes (see U.S. Pat. No. 8,096,915, for example). The Ravigneaux type planetary gear mechanism that is a component of this multi-stage transmission includes an input element (carrier) continuously coupled to an input shaft to which power is transmitted from a motor, a fixable element (front sun gear) that is selectively held stationary by a brake, a first output element (ring gear), and a second output element (rear sun gear). The first output element of the Ravigneaux type planetary gear mechanism is selectively connected via a first clutch (symbol 26) to a sun gear of one planetary gear (symbol 20) of the two planetary gears that is disposed posteriorly in the vehicle so as to be separated apart from the Ravigneaux type planetary gear mechanism. The second output element of the Ravigneaux type planetary gear mechanism that rotates at a higher speed than the first output element when the vehicle travels forward is selectively connected to the sun gear of the one planetary gear via a second clutch (symbol 28). Furthermore, the first output element of the Ravigneaux type planetary gear mechanism is selectively connected to a ring gear of the one planetary gear via a third clutch (symbol 32).